Given 17x≡1(mod23)
How to solve this linear congruence?
All hints are welcome.
edit:
I know the Euclidean Algorithm and know how to solve the equation 17m+23n=1
but I don't know how to compute x with the use of m or n.
Answer
To do modular division I do this:
an - bm = c where c is dividend, b is modulo and a is divisor, then n is quotient
17n - 23m = 1
Then using euclidean algorithm, reduce to gcd(a,b) and record each calculation
As described by http://mathworld.wolfram.com/DiophantineEquation.html
17 23 14 19
17 6 14 5
11 6 9 5
5 6 4 5
5 1 4 1
1 1 0 1
Left column is euclidean algorithm, Right column is reverse procedure
Therefore 17∗19−23∗14=1, i.e. n=19 and m=14.
The result is that 1/17 ≡ 19 mod 23
this method might not be as quick as the other posts, but this is what I have implemented in code. The others could also be, but I thought I would share my method.
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